Mile 18.5 - Boulder Narrows

An enormous house-sized boulder rests in the river here. In 1957, during the last pre Glen Canyon Dam spring flood, the river rose to over 150,000 cubic feet per second in flow. In 1983, as the reservoir behind Glen Canyon Dam reached full-capacity; large winter snowpack, an unusually warm spring, and poor judgement; created a situation where the dam itself was quickly put in jeopardy. Dam operators were forced to rush water out of the reservoir and through Grand Canyon as swiftly as possible. During the month of June, flows peaked at over 90,000 cubic feet per second. Water lapped at the driftwood on top of the massive boulder, but stayed in place. The driftwood pile is still resting on the boulder and is visible to river runners today.